Tool-grinding guide and protector assembly

ABSTRACT

A grinding-protection shroud and guide unit for attachment to a grinding machine for grinding fluted tools, especially tapered end mills having a finger-guide support horizontally adjustable relative to the grinding wheel, the shroud encompassing more than 180 degrees of the wheel and including an extended portion with a light and a vacuum-hose connector.

United States Patent Stanaback [451 Sept. 16, 1975 1 TOOL-GRINDING GUIDE AND PROTECTOR ASSEMBLY [76] Inventor: Kenneth P. Stanaback, 3640 Breton Rd., Grand Rapids, Mich. 49501 [22] Filed: Jan. 21, 1974 [21] Appl. No: 435,260

[52] US. Cl. 51/95 LH; 51/273; 51/288 [51] Int. Cl. B24B 3/12; B24B 55/06 [58] Field of Search 51/95 Ll-l, 273, 288

[56] References Cited UNITED STATES PATENTS 636,540 12/1899 Loudcn 51/95 LH UX 1,542,624 6/1925 McClclland.... 51/95 LH 1,694,074 12/1928 Martone 51/95 LH 1,834,972 12/1931 Satterstrom. 51/94 LH 1,897,035 2/1933 Anderson 51/95 LH 1,955,636 4/1934 Kistner 51/95 LH 2,422,475 6/1947 De Vlieg 51/288 X 2,789,404 4/1957 Downing et al.. 51/273 2,850,849 9/1958 Babbitt 51/95 LH 3,117,399 1/1964 Schoeppell 51/95 LH X Primary ExaminerAl Lawrence Smith Assistant Examiner-Marc R. Davidson Attorney, Agent, or F irmPrice, Heneveld, Huizenga & Cooper 5 7 ABSTRACT A grinding-protection shroud and guide unit for attachment to a grinding machine for grinding fluted tools, especially tapered end mills having a fingerguide support horizontally adjustable relative to the grinding wheel, the shroud encompassing more than 180 degrees of the wheel and including an extended portion with a light and a vacuum-hose connector.

6 Claims, 7 Drawing Figures PATENTEDSEPIEWS Q 90% 159 SHEET 2 [1F 3 FIG.4

FIG. 5

PATENTEU SEP I 61975 saw 3 a? 3 OOO FIG.

FIG. 7

TOOL-GRINDING GUIDE AND PROTECTOR ASSEMBLY BACKGROUND OF THE INVENTION This invention relates to apparatus for grinding fluted tools, and more particularly to a grinding protection and guide unit for attachment to a grinding machine for grinding fluted tools, especially tapered end mills.

In the manufacture and sharpening of fluted tools, particularly tapered, fluted end mills, the flutes are ground along the helical outer face to impart a sharp cutting edge on the apex of the flute. To do this, it is conventional to mount the tool on coaxial centers and advance it linearly and rotationally, at an angle, past the peripheral face of an engaging grinding wheel. When grinding tapered end mills, the amount of rotation per unit of linear advancement must be gradually and continually varied over the length of the flute. This varying amount of rotation with linear advancement is normally governed by the positioning of a pointed finger guide spaced some thousandths of an inch from the face of the grinding wheel to engage the inside of the flute closely adjacent the grinding wheel and the flute apex, i.e., the flute edge or apex advances in the small space between the finger guide and the grinding-wheel face. This finger guide and its support block is conventionally mounted to the head of the grinder by a pivot bolt or the like. As the wheel wears away with repeated grinding of successive tools, the operator periodically strikes the finger guide, usually with a wrench or the like, in the direction of the wheel. This is to shift the guide on its pivot bolt toward the receiving wheel surface, hopefully resulting in the guide tip being spaced a few thousandths of an inch from the wheel, i.e., not against the wheel, not so close to the wheel as to prevent the tool flute edge from moving through the space,

and not so far from the wheel that the guiding action is poorly maintained. An experienced operator, with considerable care, a sharp eye, and somewhat controlled striking of the guide, can keep a somewhat rea sonable tolerance spacing of the guide relative to the wheel. He must be cautious not to strike the high speed wheel with his wrench or other striking tool.

However, as is known in the trade, the difficulty in maintaining a constant clearance causes each tool of a group nominally identified as a particular size to actually be unique, i.e. each tool to be a bastard relataive to the others. This is clearly understandable because of the extreme difficulty in maintaining a constant spacing between the guide finger and the wheel. In fact, the varying products of a novice grinder are all too evident. Moreover, it has been determined that the arcuate pattern of the adjusting movement of the finger guide imposes another variable parameter onto the operation, imparting further differential between the tools successively machined. When such varying tools are later resharpened, after having been used, following the original grind pattern somewhat unique to each tool is particularly tricky and difficult, and often impossible. Of course a conscientious, skilled operator, when working under these circumstances, makes substantial efforts to minimize the variance between tools so ground, including working very closely to his highspeed grinding wheel to constantly visually inspect and manually adjust the spacing of the guide. The degree of protection from injury afforded to this skilled operator is therefore restricted by the nature of the grinding operation, coupled with his special efforts working closely to the wheel to optimize results.

SUMMARY OF THE INVENTION An important object of this invention is to provide apparatus for grinding helical flutes enabling relative uniformity of product to be achieved, and to be achieved with controlled adjustment of the finger guide relative to the grinding wheel. Adjustment need not be made by striking the finger guide with a wrench or the like swung close to the grinding wheel. The adjustment is linear, moreover, rather than arcuate, in a manner achieving a constant vertical position of the fingerguide tip relative to the centerline of the wheel so that, even with wheel wear, the nature of the grinding operation on each successive tool is not significantly different. With the invention, even a novice grinder can achieve good results, with succeeding tools ground on a steadily wearing and/or dressed tool being basically uniform. The tools then cut basically'alike when used. And, such tools can be more readily resharpended by I grinding after use, it being easier to follow the constant original grinding pattern.

Another important object of this invention is to provide grinding apparatus for helically fluted tools, which affords more protection for the operator. A unitary shroud encompasses more than of the wheel, mounts and orients the dust-removal suction-hose coupling, supports the work-illuminating light source, and mounts the finger-guide support in a manner allowing controlled linear adjustment without the operator having to unnecessarily expose himself to the grinding wheel or particles thrown therefrom. The cooperative connection of the finger guide support and the shroud effects this linear adjustment at a constant vertical spacing relative to the wheel centerline.

These and several other objects of the invention will be apparent upon studying the following specification in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the novel apparatus, depicting the combination of a grinding machine and the novel grinding protection and guide unit;

FIG. 2 is a perspective view of the apparatus in FIG. 1 from a slightly different angle, with the front cover having been removed from the grinding protection and guide unit;

FIG. 3 is a perspective view of the apparatus in FIGS. 1 and 2 from the opposite direction as in FIG. 2;

FIG. 4 is a slightly enlarged, elevational view of the backside of the grinding protection and guide unit itself depicted as part of the combination in FIGS. 1-3;

FIG. 5 is a front elevational view of the unit in FIG.

FIG. 6 is an end elevational view taken from the right end of FIG. 5 (i.e., the left end of FIG. 4); and

FIG. 7 is a diagrammatic elevational view showing the positioning of the fluted tool, grinding wheel and finger guide in operation and the positioning thereof relative to the grinding machine table surface.

DESCRIPTION OF THE PREFERRED EMBODIMENT This invention was devised for the grinding of tapered, fluted end mills, and hence it will basically be explained with respect thereto, it being realized that other types of workpieces could be machined using the apparatus.

The complete combination depicted in FIGS. 13 includes a grinding machine 12 in combination with the novel grinding protection and guide unit 14.

Grinding machine 12 has the typical components of a support table 16 with its platform 18 containing a key slot 20 into which the head stock 22 and tail stock 24 are attached in alignment with each other. Head stock 22 and tail stock 24 include a pair of tapered centers 26 and 28 of conventional type to rotatably support a tapered, fluted end mill or other like workpiece W therebetween. Grinding head 12 includes a driven highspeed spindle assembly 30 for mounting an abrasive grinding wheel 32 thereon.

Attached to the face of grinding head 12 adjacent grinding wheel 32 is the grinding protection and guide unit 14. This attachment is by a pair of bolts extending through openings 14b in a protruding boss 14a (FIG. 4) of unit 14, into threaded holes (not shown) in the grinding head. This unit has a housing shroud 36 which includes a curvilinearly configurated wheel covering portion 36' and an extension 36" integral therewith. Portion 36' has an opening 360 in the back side thereof (FIG. 4) to receive the grinding wheel spindle, and a surrounding collar 36d (FIGS. 5 & 6) to slide over the conventional spindle collar. This housing shroud includes a front cover 36a (FIG. 1) held to the remainder of the structure by suitable bolts and wing nuts 38. Curvilinearly configurated wheel covering portion 36 encircles greater than 180 of the grinding wheel, providing safety and leaving exposed only a small portion of the wheel necessary for the machine operation and observation thereof. Extension 36" includes in its upper surface exhaust hose coupling means 40 for securement of the exhaust hose 42 thereto, the hose being communicable with the zone adjacent the grinding wheel by an opening through the top plate of extension 36". Hose 42 communicates with suitable suction means (not shown). Also projecting through this top panel is a lightsource means including a light socket 44 with its control switch 46 and a bulb 48 projecting beneath the top panel for illumination of the grinding wheel and work. The bulb is protected by a translucent, optionally transparent, panel 50 between the bulb and wheel.

Projecting downwardly from inside the shroud exten sion is a pointed finger guide 60. It is retained in a vertically oriented, cylindrical, finger guide receiving means or socket 62' in finger guide support block 62 by a set screw 64 (FIG. 7). One end of the support block 62 has the finger guide projecting downwardly therefrom. The opposite end is secured to an elongated, horizontally extending bearing slide plate 68 by a bolt 70. Plate 68 is controllably horizontally movable relative to the housing shroud. Plate 68 is secured to the housing shroud against lubricious polymeric upper button bearings 72 and an elongated lubricious polymeric lower bearing 74 which is triangular in cross section. Bearing plate 68 has elongated upper and lower slots 68a and 68b (FIG. 4) to receive studs 76 on the shroud. Plate 68 is normally retained against movement on the shroud by tightening of a pair of nuts 78 on a pair of studs 76. A pair of coil compression springs 75 surround studs 76, positioned between washers 77 adjacent nuts 78 and plate 68 to retain holding compression on the plate to allow the bearing plate to be horizontally adjusted on the polymeric bearings. This adjustment is controlled by a rotational-screw mechanism 82 (FIG. 3) which has a gripping knob 84 at its outer end, is rotatably mounted but axially fixed to the housing shroud at its intermediate portion 86, and has a threaded portion 88 in threaded relationship with a transverse projection 68 on plate 68 (FIG. 3).

In order to grind the flutes of a tapered end mill, the end mill is mounted with its smaller end in head stock 22 and its larger end in tail stock 24, on centers 26 and 28 respectively, so as to freely rotate. The angle of the axis of the tapered end mill to the face of the grindingwheel periphery is adjusted so that it equals the angle of taper, i.e., so that the end mill surface is parallel to the grinding wheel face. The centerline Z of the workpiece W (FIG. 7) is then vertically adjusted by raising or lowering the grinding wheel with the conventional adjusting mechanism 13 on grinding head 12, until the edge of the flute to be sharpened (See FIG. 7) is on the horizontal plane A that includes the centerline of grinding wheel 32 and spindle 30. Then, turning screw knob 84, bearing plate 68 is caused to move controllably along the horizontally extending guide-bearing means on the back face of rear panel 36b of the housing shroud until the pointed lower end of guide finger is spaced a few thousandths of an inch from the grinding-wheel periphery. The guide finger is vertically adjusted by loosening set screw 64 and positioning the finger with its lower, pointed end in engagement with the inside surface of the flute to be ground, immediately adjacent the grinding wheel as illustrated in FIG. 7, i.e., a few thousands of an inch from the flute apex and the grinding-wheel surface. Thus, the very apex of the flute projects slightly into the small space of a few thousandths of an inch between the lower tip of the guide finger and the face of the grinding-wheel periphery.

Once this vertical adjustment is made, the main body of the guide finger can subsequently be horizontally ad justed as desired along the line B (FIG. 7), with the lower tip always remaining in plane A which also contains the centerline of the spindle and wheel. Also, the centerline Z of workpiece W maintains a constant vertical spacing P from the centerline of the spindle and the tip of the guide finger 60, even when the wheel wears or is purposely dressed, or when the workpiece is moved along its axis, or when the guide finger 60 is horizontally adjusted to accommodate wheel wear and- /or dressing.

When the components are arranged as depicted in FIG. 7 and described above, the grinding wheel is operated and the feed is actuated on platform 18 to advance the workpiece linearly along the face of the grinding wheel using the conventional feed mechanism (not shown) typical of grinding machines. As the workpiece advances linearly, it is caused to rotate by the engagement of the tip of guide finger 60 with the inside facialedge portion near the apex of the flute of the workpiece W. The amount of rotation per linear feed will controllably vary constantly over the length of the workpiece flutes, as governed by the engagement of the guide finger itself.

The particles of debris removed from the workpiece and/or the grinding wheel during operation are sucked out of the area through the tube 42 for disposal. The workpiece and grinding wheel are illuminated by the light bulb. The worker is protected from the grinding wheel by the shroud structure. Any adjustment of the finger guide is accurately achieved without the workman having to swing a tool next to the grinding wheel, but simply by adjusting screw knob 84 until the finger guide is in the correct position. Repeated adjustment of the finger guide relative to the wheel always results in the finger guide maintaining a constant vertical relationship relative to the table and the workpiece centerline as well as the grinding wheel and its spindle. Hence, accurate results can be repeatedly obtained when initially grinding the workpiece. Further, regrinding a dull tool can be accurately achieved because of the standardization of the tool in the first place, and the use of this novel structure for regrinding, with its repeatability of results.

Certain additional advantages and features will un doubtedly occur to those in the art upon reviewing this disclosure. It is intended that this preferred, depicted embodiment is illustrative of the invention which is to be limited only by the scope of the appended claims and the reasonable equivalents to those structures defined therein.

The embodiments of the invention in which an exclusive property or privelege is claimed are defined as follows:

l. A grinding-wheel shroud unit comprising:

a supporting shroud having attachment means for securement to a grinding machine adjacent a grinding wheel including means for receiving a grindingwheel spindle therein to remain in fixed relation thereto; a finger guide and a finger-guide-support means for retaining said finger guide closely adjacent a grinding wheel on the grinding machine; coupling and alignment means between said fingerguide-support means and said supporting shroud, including horizontally extending, configurated guide-bearing means, for restraining movement of said finger-guide'support means and said finger guide to linear, horizontal-adjustment movement relative to said shroud and to the grinding wheel and spindle.

2. The shroud unit in claim 1 including a threaded adjustment means for moving said finger-guide-support means along said horizontally extending guide-bearing means.

3. The shroud unit in claim 1 wherein said fingerguide-support means includes vertically oriented finger-guide-receiving means, and releasing finger-guidelocking means, enabling vertical adjustment of said finger guide.

4. A grinding assembly for grinding fluted tools, comprising;

a grinding machine with a horizontal spindle for a grinding wheel, a bed and tool retention center therein for retaining a fluted tool on a horizontal axis at an angle to the grinding periphery of a wheel on said spindle; a housing shroud having a wheel covering portion and an extension therefrom, said shroud being attached to said grinding machine; a finger guide and finger-guide-support means retaining said finger guide and attached to said housing shroud with releasable coupling means, said releasable coupling means including horizontally extending, configurated guide-bearing means, for restraining movement of said finger-guide-support means and said finger guide to that of horizontally linear relative to said spindle when said coupling means is released, in a manner that said fingerguidesupport means and said finger guide stay at constant elevations relative to said spindle.

5. The assembly in claim 4 including exhaust hose coupling means and light-source-mounting means on said extension.

6. A grinding assembly for grinding fluted tools, comprising:

a grinding machine with a rotational spindle for a grinding wheel, a bed and tool-retention-center means for retaining a fluted tool on an axis at an angle to the grinding periphery of a wheel on said spindle; a housing; a finger guide for engaging flutes of the fluted tool, and finger-guide-support means attached to said housing with releasable coupling means and retaining said finger guide; and said releasable coupling means including horizontally extending, configurated guide-bearing means, for restraining movement of said finger-guidesupport means and said finger guide to a linear motion relative to said spindle when said coupling means is released. 

1. A grinding-wheel shroud unit comprising: a supporting shroud having attachment means for securement to a grinding machine adjacent a grinding wheel including means for receiving a grinding-wheel spindle therein to remain in fixed relation thereto; a finger guide and a finger-guide-support means for retaining said finger guide closely adjacent a grinding wheel on the grinding machine; coupling and alignment means between said finger-guide-support means and said supporting shroud, including horizontally extending, configurated guide-bearing means, for restraining movement of said finger-guide-support means and said finger guide to linear, horizontal-adjustment movement relative to said shroud and to the grinding wheel and spindle.
 2. The shroud unit in claim 1 including a threaded adjustment means for moving said finger-guide-support means along said horizontally extending guide-bearing means.
 3. The shroud unit in claim 1 wherein said finger-guide-support means includes vertically oriented finger-guide-receiving means, and releasing finger-guide-locking means, enabling vertical adjustment of said finger guide.
 4. A grinding assembly for grinding fluted tools, comprising; a grinding machine with a horizontal spindle for a grinding wheel, a bed and tool retention center therein for retaining a fluted tool on a horizontal axis at an angle to the grinding periphery of a wheel on said spindle; a housing shroud having a wheel covering portion and an extension therefrom, said shroud being attached to said grinding machine; a finger guide and finger-guide-support means retaining said finger guide and attached to said housing shroud with releasable coupling means, said releasable coupling means including horizontally extending, configurated guide-bearing means, for restraining movement of said finger-guide-support means and said finger guide to that of horizontally linear relative to said spindle when said coupling means is released, in a manner that said finger-guide-support means and said finger guide stay at constant elevations relative to said spindle.
 5. The assembly in claim 4 including exhaust hose coupling means and light-source-mounting means on said extension.
 6. A grinding assembly for grinding fluted tools, comprising: a grinding machine with a rotational spindle for a grinding wheel, a bed and tool-retention-center means for retaining a fluted tool on an axis at an angle to the grinding periphery of a wheel on said spindle; a housing; a finger guide for engaging flutes of the fluted tool, and finger-guide-support means attached to said housing with releasable coupling means and retaining said finger guide; and said releasable coupling means including horizontally extending, configurated guide-bearing means, for restraining movement of said finger-guide-support means and said finger guide to a linear motion relative to said spindle when said coupling means is released. 